The invention relates to a fuel cell element or sensor for the measurement of gas content in gas streams. More particularly, it relates to an electrode for such a fuel cell element and a fuel cell element including the electrode.
Industrial uses of gases such as hydrogen or acetylene require sensors for monitoring leaks and for measuring concentrations. One such device is sold under the trade name Hydran and is devoted primarily to continuous monitoring of slowly variable hydrogen concentrations. The performance of fuel cell elements is dependent on the properties of the electrodes used in the element. The electrodes in the Hydran sensor include two similar circular electrodes compressed on a polypropylene spacer having a central circular aperture filled with an electrolyte. The electrodes are cut by punching from larger electrode sheets. To meet the requirements for power fuel cell applications, the electrodes are designed to obtain maximum power at high current while maintaining minimum polarization. Fuel cell elements for use in a sensor for sensing certain gases such as hydrogen, however, require electrodes working at very low current densities with maximum concentration polarization.